The Optical Magic Lantern Journal (February 1892)

The Optical Magic Lantern Journal and Photographic Enlarger. 17 Size of Disc for a Room. By J.G. Ht. As the screen is one of the very necessary parts of a lanternist’s outfit, I am glad to see that the subject of opaque screens has lately been receiving attention in the columns of this our journal. The screen is an article upon which I have expended more money than I could easily afford, | and have made various kinds of frames for supporting the sheet ; and ifa portable concern is required, that described by Mr. Hilton Grundy, | in the issue for Jan. 1891, 1s the most convenient I have everseen. As soon as I read his instructions I made one, but with brass angle joints instead of zinc as recommended. This I have had in constant use ever since, but it even has a great drawback, and in the case of lanternists who, like myself, use the lanternina domestic sense, the same also applies, for tables and chairs require to be moved to one side in order to rig up the screen on the floor before erecting it to the upright position. A great many of my friends use the lantern in what I might call the domestic sense, but they all err in the same direction as I myself have done—viz., too large a disc, and I think Iam not far wrong in saying that pictures from 7ft. to oft. | across are what is in inany cases aimed at. Now to properly examine and enjoy a picture of this size in the parlour of an average dwelling is simply an impossibility, for it would be necessary for the spectators to be farther off from the screen than the walls of the room would allow. At close quarters, not only does the picture appear fuzzy—or what some people term naturalistic—but a great strain is put upon the eyes also, and one speedily grows weary of seeing large pictures at such close quarters. [have with great advantage made a permanent screen in my parlour which is not only handy for | use at a moment's notice, but which answers the purpose much more satisfactorily than my previous one. It is much smaller and, above all, opaque, and for experimental work, it is all that could be desired, and my friends state that the pictures can be seen not only more distinctly than with my old screen, but that the eye is relieved from all strain. Now, as to the style of the screen: between the two windows of the room spoken of there is a space of 4ft. On this, at the required height, I have pasted what is known in the paper-hanging line as white lining paper, and around the fourfoot square thus formed, have pasted a fancy border. In front of this I stand a what-not which merely requires to be lifted to one side when I use the screen. As the window curtains extend slightly over the screen, it is not noticable unless attention b2 called to it. —eo—— Cause of Oil Lamps Burning imperfectly. By Rev. Water H. Grecory. Ix “ Notes and Queries” I observe that a correspondent seeks aid in respect to two of his wicks burning dimly after the lamp had been burning I for a little time, until there was no light worth speaking of. he answer given was to the effect that the oil supply was insufficient, or the wicks too short. The correspondent, “F. J. B.,” has touched upon one of the greatest difficulties in the working of an oil lantern. His experience ‘is that of many others, and the fault is neither in the oil, wicks, lantern, or manipulator. The hindrance to a successful light is entirely atmospheric. No oil light can live in impure air. I use a four-wick lamp, and under certain conditions have produced a light to almost equal lime-light. During last March I gave aseries of lectures, and on each evening the lamp burned splendidly and gave an excellent light, all four of the wicks doing their duty conscientiously. On_ these occasions the air was clear, and the conditions of the room were all one could desire. Now, contrast this with a series of missionary lectures I gave at a different time of the year. During last November I used the same lantern which in March had answered so admirably ; and what with the fog, and the heating of the room ' by fire, gas, and people, the air became so impure that two of the wicks refused to burn. On December 26, at a crowded children’s entertainment, these conditions were so terrible that the result was failure—not one of the wicks i would burn with any effect; they trembled like aspen leaves. I feel assured that the only explanation “ F. J. B.” can find is that it is due to the density of the atmosphere, thus preventing a sufficient current of pure air to the lights. As the lantern is mostly used at that time of the year when atmospheric conditions are at their worst, the only remedy is to employ lime-light. SouTtH LONDON PHOTOGRAPHIC Socrety.—We are | informed that Mr. C. H. Oakden, of 51, Melbourne-grove, East Dulwich, has been appointed hon. sec, of the above society, in the place of Mr. S. W. Gardner, who has resigned,